When is the last time that you changed your brake fluid? If you can’t answer this simple question, then you probably never done this task before.
Flushing or bleeding your brake fluid is as essential (or even much more important) as your regular engine oil change.
Remember, your life depends on how your braking system perform. The better your brakes work, the more you survive the road. Otherwise, it could be deadly fatal for someone who is driving a broken braking system.
In this short post, I will discuss to you how you can bleed or flush your brake fluid properly. But lets ask this question first.
Why You Should Check Your Brake Fluid?
The very importance of keeping your brake fluid in good condition is not an exaggeration to say that it is the most important maintenance job in your vehicle.
Brake failure occurs primarily with bad or severely depleted brake fluid system. So you have to prioritize this task on your preventive maintenance schedule.
It is highly important that you check your brake fluid at least once a month to ensure that there is no leak in your braking system, especially if you have an old car.
You have to maintain your brake fluid clean, fresh and free of water and other chemical contaminants.
Dot 3 and Dot 4 brake fluids are mostly clear in color, while Dot 5 or higher can be purple . All brake fluids are hygroscopic, meaning that they absorb water overtime.
So if you don’t change your brake fluid, more water can be absorbed in the system and may cause air compression during braking (as brake system gets too hot and water’s boiling point is much lower than brake fluid).
This may cause brake failure.
Where to check your brake fluid? Go to your car’s brake master cylinder, where your brake fluid reservoir seats in.
When to Change Brake Fluid?
If your owner’s manual requires a Dot 3 or 4, then you should see a clear colored fluid inside your reservoir.
But if you see colored fluid such as black or reddish color, then it is time to change or flush your entire brake fluid system.
And as mentioned above, excessive water contamination causes your pedal to feel spongy or soft. If too much pedal is required to stop your vehicle, then it is also a sign of water contamination inside your car’s braking system.
Another reason to change your brake fluid is increased stopping distances. Though there are dozens of causes for this, the main reason is still bad, discolored and dirty fluid.
So if your car sounds like any of these, then it is time to change your brake fluid immediately.
How to Flush / Bleed Your Brakes?
First, you need to know that there are two kinds of brakes in cars today – drum and disc brakes.
Disc brakes are now more common in modern cars but some manufacturers still use drum brakes to lower their manufacturing costs. That’s why you still see cheap cars with drum brakes at the rear wheels.
The image above is a sample drum brake. That view is the back side of drum brakes exposing the bleeder valve at the top.
The tools you need for this job are as follows:
- Turkey baster
- A plastic bottle
- Level hose
- 8 and 10mm wrench
- Brake fluid Dot 3 or 4
- Gloves and
- Eye goggles
So there is two methods that you can do to bleed your brakes. First is called the one-man method, which you bleed your brakes on your own.
The second method is called the two-person method where you need someone to assist you while you are opening the bleeder valves.
I will discuss the one-man method here as this is the most practical and fastest way to flush/bleed your brakes.
Here are the correct sequence to bleed your car’s brake fluid:
- Suck the fluid in the brake master cylinder
- Bleed the farthest brake – right, rear wheel
- Refill the brake master cylinder with fresh fluid
- Bleed the left, rear wheel
- Refill the brake master cylinder with fresh fluid
- Bleed the front passenger wheel
- Refill the brake master cylinder with fresh fluid
- Bleed the driver’s side wheel
- Refill the brake master cylinder with fresh fluid
Use your Turkey baster to suck out the old fluid from your brake master cylinder. Make sure that you don’t completely dry the reservoir.
Close the cap and go to the farthest wheel from the brake master cylinder, which is the right, rear wheel. Some folks may say other method but this is the commonly followed rule by most mechanics.
You may remove the tire if you want a better look of the bleeder valve (which is behind the disc calipers and drums. But actually, you don’t have to remove your tires.
Next is to locate the bleeder valve (as pictured above). It is sealed by an oil rubber dust seal. Just take the rubber off and the valve will be exposed.
Use your level hose and insert it unto the bleeder valve. Make sure that it is tight and fit. Otherwise, you may use a cable tie to tighten the hose to the valve.
Turn the valve counter clockwise using your 8 or 10mm wrench. Once opened, you will see the old fluid coming out of the valve.
Now go inside the driver’s cabin and press on the brake pedal for about 10 to 15 times.
Go back underneath the car and see if your bleeding bottle has accumulated old fluid. If the fluid in the level hose is clear, then you are good to go and close the bleeder valve. Don’t forget to place the oil seal back too.
Now check the brake master cylinder if it runs our of fluid. Refill the reservoir with fresh fluid then continue bleeding the next three wheels.
The procedures for the three wheels are the same until you are finish. Remember to fill the brake master cylinder to its maximum level before you test drive.
After you test drive your car, take a look underneath your wheels and see if there are leaks. If all looks fine, then you are done bleeding your brakes!
Here is a detailed video of how I flushed my car’s brake fluid system. This video is in Tagalog language, but it has English caption.
Enjoy!
